Cardiac pacing is delivered to patients to treat a wide variety of cardiac dysfunctions. Cardiac pacing is often delivered by an implantable medical device (IMD), which may also provide cardioversion or defibrillation, if needed. The IMD delivers such stimulation to the heart via electrodes located on one or more leads, which are typically intracardiac leads.
Patients with heart failure are often treated with cardiac resynchronization therapy (CRT). CRT is a form of cardiac pacing. In some examples, CRT involves delivery of pacing pulses to both ventricles to synchronize their contraction. In other examples, CRT involves delivery of pacing pulses to one ventricle, such as the left ventricle, to synchronize its contraction with that of the other, e.g., right, ventricle.